Hearing Helper Personal FM Receiver • Model PFM R31
Maximize a student’s ability to listen with the Personal FM R31 receiver from Williams Sound. The
PFM R31 will ensure that everyone in the classroom can hear the speaker’s message clearly and easily.
Each receiver has a range of up to 150 feet, and will operate up to 80 continuous hours. Versatile 3.5
mm jack allows for a variety of earphone and headphone options, or, equip it with a neckloop to
make it compatible with most telecoil-equipped hearing aids.
The PFM R31 features a sensitive environmental microphone which gives the listener more flexibility
on what they want to hear. By turning on the environmental mic, they can listen to a nearby class-
mate speak more clearly.
Classrooms • Job Consultation • Job Training • Tours • Group Meetings
PFM R31 FM Receiver:
Mic Jack Indicator
3-5/8" L x 2-3/8" W x 7/8" H (92.1 mm x 60.3 mm x 22.2 mm)
4.6 oz (130 g) with batteries
Royal blue, shatter-resistant polypropylene
Two (2) AA 1.5 V non-rechargeable Alkaline batteries (BAT 001),
4 mA nom. current drain, 80 hours approx. life
OR) Two (2) AA 1.5 V NiMH rechargeable batteries (BAT 026),
4 mA nominal current drain, 50 hours per charge approx.,
recharges in 14–16 hours, uses CHG 200 Charger
Pre-tuned, field–tuneable, 72 MHz - 76 MHz*.
Pre-set channels are E (72.9 MHz) and G (75.7 MHz).
Wide-band, 75 kHz, 75 µS de-emphasis
± 120 kHz
4 µV at 12 dB Sinad with squelch defeated,
squelches at 10 µV for min. 50 dB S/N ratio
100 to 10 kHz, + 3 dB
50 dB at 10 uV
Integral with earphone cord
35 mW, max. at 16 Ω
3.5 mm mono phone jack
Set to turn off audio under weak or no signal condition
Red LED, turns on in the presence of a carrier
Carrier Detect Ind:
3-way slide switch; Lo: flat response (20 Hz), Mid: -3 dB at 235
Hz, Hi: -3 dB at 730 Hz
2-way slide switch; Ch 1 = 72.9 MHz, Ch 2 = 75.7 MHz
On/Off and FM
1 or 2
3.5 mm mono phone jack, supplies positive DC for Williams
Sound electret mics
Plug mount electret, omnidirectional, with windscreen, 3.5 mm
mono phone plug (MIC 014)
Specifications are electrical performance
5 years, parts and labor**
FOR THE HANDICAPPED.
DISCLAIMER: FCC RULES LIMIT USE OF THIS EQUIPMENT TO AUDITORY ASSISTANCE
**90 days on accessories.
NOTE: SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE!
©2007, Williams Sound Corp. MCAT 005B